Punched card reader



May 23, 1967 Filed April 5, 1965 N. R. TIMARES PUNCHED CARD READER 2Sheets-Sheet 1 oo o 000 0000 INVENTOR NORMA/V R. 7'/MA/?5 BY QM? m ATron/v5) y 23, 1967 I N. R. TIMARES 3,321,591

PUNCHED CARD READER Filed April 5, 1965 2 Sheets-Sheet 2 i 5- //vl/vr0/e NORMAN R, 77MAREI A FOE/V5) United States Patent 3,3215% PUNCHEDCARD READER Norman R. Timares, lLos Aug-tales, Calif, assignor to FMA,Inc., Los Angeles, Calif. Filed Apr. 5, 1965, Ser. No. 445,385 4 Claims.(Cl. 200-46) The present invention relates to improved punched cardreader apparatus. In particular, the present invention is an improvementof the apparatus disclosed in Patent No. 3,144,525, issued to George S.Penn and Robert F. Kiddle on Aug. 11, 1964 and entitled Punched CardReader.

With respect to said patent, when a card through which a predeterminedpattern of holes has been punched is inserted in the apparatus describedtherein, connector pins pass through the card whereat the holes arelocated and, on the other side of the card, make electrical contact insuch a manner as to produce an output pattern of voltages thatcorresponds to the pattern of punched holes on the card. The essence ofthat invention lies in the fact that on one end of the connector pinsmeans are used that insure a uniform pressure on the pins, and on theirother end means are employed that insure a uniform electrical contactfor them. In particular, in an embodiment of the invention, arubber-type pad is used to provide the spring action for the pins, and asingle metal plate is employed for making the necessary electricalcontact with them. Thus, by means of this earlier invention, theindividual spring and metal sleeve elements so common in the prior artwere eliminated and so were the attendant limitations.

However, although the punched card reader apparatus disclosed in Patent3,144,525 was a marked improvement over other such devices found in theprior art, the user of this apparatus nevertheless encountered a rathertroublesome problem in that, with continued use, lint, dust, and otherforeign elements and impurities would become lodged between the plateand the connector pins so that poor electrical contact would be madebetween them, with the resultant etfect that the output voltages, ifobtained at all, would be of relatively poor quality. This, obviously,

could only produce poor or erroneous results in whatever system suchapparatus was being used.

The present invention improves over this earlier punched card readerapparatus by insuring good electrical contact between the plate and thepins at all times, irrespective of the length of the period of use. Morespecifically, in accordance with the concept of the present invention,this is done or achieved by insuring that each connector pin contactsthe metal plate at least at two points and, furthermore, that a certainwiper action will take place between these two parts before relativemotion between them terminates. Although the subject invention may beconstructed in any one of several ways, in a preferred embodiment of ita series of grooves are incorporated in the plate structure, the groovespreferably extending across the full length of the plate and beingshaped in such a manner that as the connector pins move through theholes of a punched card, they respectively come into contact with andwipe against one wall of the grooves, and then the other groove wall,and finally come to rest in firm mechanical and electrical contact withboth walls. It is thus seen that by means of this technique, theaforementioned problems are eliminated.

The .novel features which are believed to be characteristic of theinvention, both as to its organization and mode of operation, togetherwith further advantages thereof, will be better understood from thefollowing description considered in connection with the accompanyingdrawings in which an embodiment of the invention is illustrated by wayof example. It is to be expressly understood, however, that the drawingis for the purpose of illustration and description only, and is notintended as a definition of the limits of the invention.

FIGURE 1 shows a card through which a pattern of holes has been punched;

FIGURE 2 presents a crosssectional view of a punched card readerapparatus according to the present invention;

FIGURE 3 is a top view of the contact plate for the purpose ofillustrating the several grooves therein;

FIGURE 4 is an enlarged view of the tip of connector pin and itsassociated grooves in the contact plate, and illustrates therelationship therebetween as the former moves into the latter; and

FIGURE 5 is an enlarged view of the tip of a connector pin after it hascome to rest in its associated groove in the contact plate.

Reference is made first to the punched card shown in FIG. 1, the carditself being designated 10, and the holes thercthrough being designated11. The pattern in which holes 11 are arranged is in accordance with apredetermined code, while the size of and the spacing between adjacentholes respectively correspond to the thickness or diameter of theconnector pins and the spacings between them. In the particular cardbeing shown, the holes are arranged in columns and rows, and thediscussion of the punched card reader apparatus that follows will bewith this arrangement in mind.

In FIG. 2, the card reader is shown to include a metal contact plate 12mounted on an insulative board 13, the plate and board combination, inturn, being fixedly mounted on a base 14 which may or may not be metaland which constitutes a part of the housing structure for the cardreader. As is shown in the figure, contact plate 12 includes a pluralityof grooves 12a with convexly curved side walls formed in its topsurface, there being as many of these grooves as rows of connector pins,as will be more fully explained later.

Also mounted on base 14 and of the same thickness as the plate 12 andboard 13 combination is a plate or board 15, board 15 being mounted onbase 14 in such a manner that it overhangs the base in a cantileveredfashion. Fixedly mounted above contact plate 12 and board 15 and inface-to-face relationship with them is still another plate or boardmember 16 made of an insulative material. The spacing between plate 12and board 15 on theone hand and member 16 on the other hand is onlyenough to permit a punched or perforated card 10 to be inserted in thespace therebetween, and it is for this reason that element 15 iscantilevered, namely, to facilitate the insertion of a card. A punchedcard 10 already inserted in the space provided for it is shown in thefigure. Finally, member 16 has as many holes or channels through it asthere are connector pins, the purpose of these channels, which aredesignated 17, being to protect and properly direct the movement of thepins into contact with the grooves in plate 12, as will be seen later.Accordingly, upon insertion of a card 10, holes or channels 17 come intoregistration with or, stated differently, respectively become positionedover all the points on the card whereat perforation-s or holes maypossibly be located. Thus, a channel 17 is positioned over each spot oncard 10 whereat a hole may be punched or is punched through it.

Also included in the card reader is a housing block 18 whose walls mayor may not be of metal and which is movably positioned above boardmember 16. Inside housing block 18 and held by the walls thereof is apinhousing block 26 that faces board member 16. Pinhousing block 20 ismade of an insulative material and has a plurality of holes or channels21 through it which respectively are in registration with holes orchannels 17 therebeneath. As may be expected, the connector pins,generally designated 22, are mounted in the extend through hole-s 21,with the result that there are as many of these holes 21 as there areconnector pins 22 and holes 17 through board 16. Finally, inside housingblock 18 and cemented or otherwise mounted to the surface of the topwall thereof is a rubber-type pad 23 whose function it is to apply aspring-type force to the connector pins with a minimum of cross-talkbetween them, specifically, a minimum between those pins that passthrough punched card it and those that do not. In turn, this is done byminimizing the differential travel of the pins between their twopossible positions.

With respect to pins 22, they respectively include a thin metal rod 22a.and a shoulder or flange element 221') that abuts against the top ofpin-housing block 20 when the bottom portion of .rod 22a has passedthrough a hole in card and come into contact with plate 12. Thus, ele-'ments 22b respectively help to limit the downward movement of theconnector pins, and they are so fabricated and positioned or located onrods 22a as to control this downward travel within very fine tolerances.Rods 22a are necessarily made of metal, whereas elements 221) may or maynot 'be made of metal. As previously indicated, rods 22:: are slidablymounted in holes 21, the extremities of the pins on one side extendingthrough channels 17 until the tips thereof are contiguous to contactplate 12. The extremities of the pins on the other sides extend upwardsuntil they come into pressure contact with pad 23. Pins 22 are roundedat their upper tips so as to reduce the possibility of damage to the padas much as possible, and they are tapered at their bottom tips so thatthey can make good electrical contact with plate 12 when they areallowed to do so, as will be explained below.

Housing block 18 may be moved slightly up or down, that is, away from ortoward board member 16, the distance through which it can be moved beingonly enough to raise pins 22 so that a punched card 1t may easily beinserted in the space between contact plate 12 and member 16. Housingblock 18 may be raised and lowered in any one of a number of ways, allof them being well known in the mechanical arts. Thus, merely by way ofexample, a simple lever apparatus may be coupled to the housing block 18to manually raise or lower very much in the same mannerias a drill bitis raised or lowered in a drill press. Since the manner in which thehousing block is raised and lowered involves a state-ofthe-artmechanical arrangement, it is not shown in the figure for the sake ofexpediency. Also not shown in the figure is a source of either positiveor negative potential connected to contact plate 12. Finally, in orderto detect or determine whether or not potentials exist in any one ormore of pins 22, leads or wires 24 are respectively electricallyconnected to the pins, the leads or wires being coupled to externalcircuitry which does not form a part of this invention.

Returning briefly to contact plate 12 and to grooves 12a formed therein,these groove extend for the full length of the plate, as is clearlyshown in the view of FIG. 3, and they are tapered and rounded convexlyalong their sides in the manner shown in FIG. 4 so as to provide thedesired wiping action and to form dual points of contact with the pins.More specifically, the shape of the grooves is detenrnined by toleranceallowances, and must meet at least three conditions, namely:

(1) Contact between a pin and groove must be dual, that is to say, mustoccur at least at two points, as previously mentioned;

(2) The shape of the grooves must allow a proper pressure angle forextreme pin positions within the allowed tolerances so that the pinswill be directed toward the center of the grooves or slots; and

(3) With respect to a feature that was previously explained, namely,that of cross-talk, the groove shape must be such as to allow a minimumof cross-talk between those pins that have passed through the holes inthe punched card and entered grooves 12a and those that have beenprevented from doing so. As was previously mentioned, this is achievedby minimizing the differential travel of the pins in these twopositions, and a proper shaping of the grooves will contribute toward aminimization of this differential travel.

in operation, prior to the time a card 10 is placed in the card reader,housing block 18 is in its raised posi; tion so that the space intowhich the car-d is inserted is free of pins 22 which might otherwiseinterfere with the proper insertion of the card. However, once a punchedcard is inserted in the space provided between elements 12 and 16, thehousing block is then lowered, and when this is done, the tips of pins22 are brought into contact with the card which, in consequence thereof,exerts an upward or backward push on the pins. More specifically, thosepins that are in registration with the holes punched through the cardwill be urged by rubber pads 23 to pass through the holes and makecontact with plate 12, it being those pins that do not pass through thecard that are pushed back by it.

It will be noticed from FIG. 2 that the pins that do not encounter holesin the card are actually moved upwards slightly as indicated by theslight spacings between tlanges 22b on these pins and the top surface ofpin-housing block 2%. This slight upward displacement of the pins istaken up by the elastic pad which indents or becomes deformed slightlyat the points whereat these pins press against the pad. As for the pinsin contact with plate 12, these pins now have the same potential on themas is found on plate 12, the signals thereby produced being fedelsewhere by means of leads 24. To remove the card, housing is raised,thereby also raising the pins and allowing room for the card to bewithdrawn. It will be recognized that upon raising the housing block,those of pins 22 that were previously moved upward by card It) will nowbe moved downward the same amount by rubber pad 24-. As a result, thebottom tips of the pins are once again in the same plane and ready forthe next punched card to be inserted. It is thus seen that by using arubber-type pad 23, the desired forces can be maintained on the pins andwith a minimum of cross-talk between them.

Considering the manner in which contact is made between plate 12 andpins 22 in greater detail, reference is once again made to PEG. 4wherein, according to the allowed tolerances of the apparatus, rod 22aof the pin illustrated therein is shown in an extreme unaligned positionwith respect to its associated groove 12a. As a resuit, as pin rod 22amoves toward groove 12a, it first strikes one side or wall of thegroove, and because of the walls curvature and taper, the pin rod isdeflected toward the grooves opposite side or wall. However, mostimportantly, before it is deflected, the rod, because of its downwardmotion, wipes or scrapes the side or wall of the groove to thereby makepossible the desired goodquality electrical contact between them.Following the above-said deflection of the pin rod, it comes intocontact with the opposite side or wall of the groove where the samewiping or scraping action takes place as the pin continues to move intothe groove, so that good-quality electrical contact is thereby alsoobtained on this side. When rod 22a has completed its travel into groove12a, it will be lodged in the groove as shown in FIG. 5, wherein is alsoshown the dual points of contact, designated 25a and 25b, between therod and the walls of the groove. It can thus be seen that by using ametal plate 12 with grooves 12a therein of the kind described, the samepotential within very accurate limits is applied to the pins, therebyreducing the possibility of errors in the output signals fed over lines24-.

Although a particular arrangement of the invention has been illustratedand described above, it is not intended that the invention be limitedthereto. Accordingly, the invention should be considered to include anyand all modifications, alterations or equivalent arrangements fallingwithin the scope of the annexed claims.

Having thus described the invention, what is claimed is:

1. A punched card reader comprising: a flat, rigid electricallyconductive plate having long, straight grooves therein with convexlycurved side walls; a plurality of electrically conductive pinsperpendicularly positioned over said plate in approximate registrationwith the grooves thereof, said pins each being tapered at the tipadjacent said plate so as to become aligned with and make contact withboth walls of said grooves when the tips thereof are moved therein;means for supporting said pins so they are axially movable and have asmall lateral play suflicient to permit contact with both walls of saidgrooves; and means for selectively applying a pressure to said pins tomove them axially into said grooves, said means including a resilientpad mounted over said pins and in contact therewith for directlyapplying said pressure.

2. A punched card reader comprising: a plurality of electricallyconductive pins, the tip of each pin being tapered to form truncatedconical sections; a flat, rigid electrically conductive plate havinglongitudinal grooves therein in approximate registration with the pins,said grooves having convexly curved walls so as to deflect the tips ofsaid pins toward the centers of the grooves upon axial movement of thepins toward the grooves and to provide two points of electrical contactbetween a pin and its groove; means for holding each pin so it isaxially movable and has a small lateral play sufiicient to permitcontact with two points of its groove; and means for selectively movingsaid pins axially into said grooves.

3. A punched card reader comprising: a flat, rigid electricallyconductive plate having longitudinal grooves therein with convexlycurved side walls, said grooves being substantially parallel to eachother and extending for the full length of said plate; a housingstructure positioned over said plate and adapted to be selectively movedtoward and away from said plate; a resilient pad mounted in said housingstructure and parallel to said plate; and a predetermined number ofelectrically conductive pins slid,- ably mounted in said housingstructure in a position that is perpendicular to both said pad and saidplate with lateral play sufficient to cause contact with both sidewallsof the grooves upon sliding the pins toward the plate, said pins beingarranged in substantially parallel rows that are in approximateregistration with said grooves, said pins being in pressure contact withsaid pad at one end and being contiguous to said plate and tapered atthe other end thereof.

4. A punched card reader comprising: a base structure that includes aflat, rigid electrically conductive plate in which longitudinal convexlycurved grooves are formed, said grooves being parallel to one anotherand extending the length of the plate, a housing structure positionedover said plate, such structure including an electrically insulativewall facing said plate and having a plurality of connector-pin holestherethrough arranged in rows that are respectively in approximateregistration with said grooves, an electrically conductive connector pinslidably positioned in and extending through each of said holes towardsaid metal plate, said connector pins each being tapered at the endfacing toward said metal plate; and a rubber-like pad mounted over saidpins and in contact therewith for applying a forward pressure thereto,said pins being held with sufficient lateral play that, in response tosaid pressure, they are forced through the holes in the punched card andinto said grooves wherein they respectively make contact with both wallsof said grooves; and means for spacing said base and housing structuresto permit a punched card to be inserted therebetween and thereafterremoved.

References Cited by the Examiner UNITED STATES PATENTS 233,968 11/1880Bergman 317-112 648,432 5/1900 Prentiss 200-166 2,389,429 11/ 1945Griffith. 2,924,685 2/1960 Burch 200-166 3,144,525 8/1964 Fenn et al200-46 3,168,635 2/1965 Gebhart 200-166 BERNARD A. GILHEANY, PrimaryExaminer.

T. MACBLAIN, H. E. SPRINGBORN,

Assistant Examiners.

1. A PUNCHED CARD READER COMPRISING: A FLAT, RIGID ELECTRICALLYCONDUCTIVE PLATE HAVING LONG, STRAIGHT GROOVES THEREIN WITH CONVEXLYCURVED SIDE WALLS; A PLURALITY OF ELECTRICALLY CONDUCTIVE PINSPERPENDICULARLY POSITIONED OVER SAID PLATE IN APPROXIMATE REGISTRATIONWITH THE GROOVES THEREOF, SAID PINS EACH BEING TAPERED AT THE TIPADJACENT SAID PLATE SO AS TO BECOME ALIGNED WITH AND MAKE CONTACT WITHBOTH WALLS OF SAID GROOVES WHEN THE TIPS THEREOF ARE MOVED THEREIN;MEANS FOR SUPPORTING SAID PINS SO THEY ARE AXIALLY MOVABLE AND HAVE ASMALL LATERAL PLAY SUFFICIENT TO PERMIT CONTACT WITH BOTH WALLS OF SAIDGROOVES; AND MEANS FOR SELECTIVELY APPLYING A PRESSURE TO SAID PINS TOMOVE THEM AXIALLY INTO SAID GROOVES, SAID MEANS INCLUDING A RESILIENTPAD MOUNTED OVER SAID PINS AND IN CONTACT THEREWITH FOR DIRECTLYAPPLYING SAID PRESSURE.